In accordance with the demand for the intelligent power supply network in China, the State Grid Corporation of China requires the power supply network to be intelligent. Therefore, a terminal actuator for the power supply network, i.e., a miniature circuit breaker (or a micro circuit breaker) is required to actuate uplink signals to provide tripping and closing functions. Hence, as the current development trend, in addition to the conventional manual opening/closing function and automatic overcurrent/overload release function, the miniature circuit breaker is further required to have an electric opening/closing function (called an automatic opening/closing function) so as to realize remote control, particularly a function of realizing, in conjunction with a smart meter, automatic tripping in arrearage and automatic power transmission with sufficient prepayment.
Since the conventional miniature electric opening/closing circuit breakers cannot meet the requirements of the power companies due to their complicated structure, proneness to fault and functional insufficiency, those skilled in the art have been focused on where the difficulty lies, that is, continuously improving the structure of the conventional miniature electric opening/closing circuit breakers in order to meet the ever higher requirements of consumers.